Many businesses rely on some form of WORM (write once, read many) data storage to store critical data. In many industries, such as the financial services and healthcare industries, businesses are required by strict records-retention regulations to archive important data, such as emails, transaction information, patient records, audit information, as well as other types of documents and data. Such records-retention regulations include, for example, Securities Exchange Commission (SEC) Rule 17a-4 (17 C.F.R. §240.17a-4(f)), which regulates broker-dealers; Health Insurance Portability and Accountability Act (HIPAA), which regulates companies in the healthcare industry; Sarbanes-Oxley (SOX), which regulates publicly traded companies; 21 C.F.R. Part 11, which regulates certain companies in the life sciences industry; and, DOD 5015.2-STD, which regulates certain government organizations; etc. Regulatory agencies generally recognize the ability of WORM data storage to ensure the permanence of archived data and therefore often require that only non-erasable, non-rewritable WORM storage be used for meeting their regulations. Software applications that manipulate data that may be subject to records-retention regulations are sometimes referred to as compliance applications.
Some existing systems (e.g., networked storage systems) provide a conventional (hierarchical) file system interface in a storage server to allow users to access stored data and to designate at least a subset of the data as WORM data through the file system interface. A networked storage system may include one or more storage servers, which may be storage appliances. A storage server may provide services related to the organization of data on mass storage devices, such as disks. Some of these storage servers are commonly referred to as filers or file servers. An example of such a storage server is any of the Filer products made by Network Appliance, Inc. in Sunnyvale, Calif. The storage appliance may be implemented with a special-purpose computer or a general-purpose computer. Depending on the application, various networked storage systems may include different numbers of storage servers. Various applications, including compliance applications, may be permitted to create and modify data on a storage appliance.
Some compliance applications do not have a built-in capability to assign a retention time to files or to commit files to WORM status. The files therefore may need to be committed to WORM status manually (e.g., by an administrator copying the files to a WORM storage device). On the other hand, some compliance applications may not have a capability to notify a storage system of when the application has completed the modifying operations on a file so that the file may be treated as closed. Furthermore, when a compliance application communicates with a storage server via open communications protocols, such as NFS or CIFS, the network traffic may not be indicative of the status of a file with respect to the status of the file as being open or closed for further modifications. For example, NFS does not have a mechanism to indicate when a file is closed. CIFS does have a mechanism of indicating that a file has been closed, but there are many applications that will close a file and then reopen it for writing again.